2. Reboot into recovery. I suggest using the RA-dream recovery you can download it here

3. Wipe your phone "factory data reset" (this step isnt really necessary since your phone is wiped after flashing the SPL but I always like to wipe before flashing anything)

DO NOT SKIP THIS NEXT STEP OR YOU WILL BRICK YOUR PHONEYou must have the latest radio "2_22_19_26I" or "2_22_23_02" to flash this SPL if you already have the latest radio you should not have to flash it again but it will not hurt if you do flash it again. When in doubt flash it anyway.

4. Flash the Radio "ota-radio-2_22_19_26I.zip" or "G1-radio-2_22_23_02.zip" it will install and then it will ask you to reboot to finish the installation, so reboot, it will then finish installing and then reboot back into recovery.

5. Flash the SPL "spl-signed.zip" it will install and then ask you to reboot to finish the installation, so reboot, it will then finish installing and reboot into recovery so you can flash your ROM

A simple way to make sure that the SPL flashed correctly is when you reboot to the boot loader screen by holding the camera button you will see HBOOT-1.33.2005. You can also see that it flashed correctly by checking your system size it will now be 89mb a very easy was to check this is with the My Account app available in the Market.

Credit Joe333x (Source)

_________________

Z.d.u.n.e.X's Stuff: [size=9]Personal Site | My skins"Whatever you do in life will be insignificant, but it's very important that you do it, because nobody else will."[/size]